How to program a telnet client? Post: 13365

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Top Forums Programming How to program a telnet client? Post 13365 by thinker130 on Wednesday 16th of January 2002 03:43:26 AM

01-16-2002

Registered User

the source files(the third part)

I have forgotten to include some functions needed in file tel_cli.c, please append the belowed source code to the end of file tel_cli.c.

/*connectsock - allocate & connect a socket using TCP or TCP*/
int connectsock(const char *host,const char *service, const char *transport)
/* arguments:
* host --- name of host to which connection is desired
* service -- service associated with the desired port
* transport --- name of transport protocol to use ("tcp" or "udp")
*/
{
struct hostent *phe; /* pointer to host information entry */
struct servent *pse; /* pointer to service information entry */
struct protoent *ppe; /* pointer to protocol information entry */
struct sockaddr_in sin; /* an Internet endpoint addredd */
int s,type; /* socket descriptor and socket type */

memset(&sin,0,sizeof(sin));
sin.sin_family=AF_INET;

/* Map service name to port number */
if (pse = getservbyname(service,transport))
sin.sin_port = pse->s_port;
else if ((sin.sin_port = htons((u_short)atoi(service))) == 0 )
{
//errexit("can't get \"%s\" service entry\n",service);
printf("can't get \"%s\" service entry\n",service);
return 0;
}

/* Map host name to IP address,allowing for dotted decimal */
if (phe = gethostbyname(host))
memcpy(&sin.sin_addr,phe->h_addr,phe->h_length);
else if ((sin.sin_addr.s_addr = inet_addr(host)) == INADDR_NONE)
{
//errexit("can't get \"%s\" protocol entry\n",transport);
printf("can't get \"%s\" protocol entry\n",transport);
return 0;
}

/* Map transport protocol name to protocol number */
if ((ppe = getprotobyname(transport))==0)
{
//errexit("can't get \"%s\" protocol entry\n",transport);
printf("can't get \"%s\" protocol entry\n",transport);
return 0;
}

/* User protocol to choose a socket type */
if (strcmp(transport,"udp") == 0)
type = SOCK_DGRAM;
else
type = SOCK_STREAM;

/*Allocate a socket */
s = socket(PF_INET, type, ppe->p_proto);
if (s < 0)
{
//errexit("can't create socket:%s\n", strerror(errno));
printf("can't create socket:%s\n", strerror(errno));
return 0;
}
/* connect the socket */
if (connect (s,(struct sockaddr *)&sin,sizeof(sin)) < 0)
{
//errexit("can't connect to %s.%s: %s\n",host,service,strerror(errno));
printf("can't connect to %s.%s: %s\n",host,service,strerror(errno));
return 0;
}
return s;

}

int connectTCP(const char *host, const char *service)
/* arguments:
* host --- name of host to which connection is desired
* service --- service associated with the desired port
*/
{
return connectsock(host,service,"tcp");
}

/* errexit --- print an error mesage and exit */

/*VARARGS1*/

int errexit(const char *format,...)
{
va_list args;
va_start(args,format);
vfprintf(stderr,format,args);
va_end(args);
exit(1);
}

thinker130

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LEARN ABOUT FREEBSD

rpcinfo

RPCINFO(8)						    BSD System Manager's Manual 						RPCINFO(8)

NAME

     rpcinfo -- report RPC information

SYNOPSIS

     rpcinfo [-m | -s] [host]
     rpcinfo [host]
     rpcinfo -T transport host prognum [versnum]
     rpcinfo -l [-T transport] host prognum [versnum]
     rpcinfo [-n portnum] -u host prognum [versnum]
     rpcinfo [-n portnum] [-t] host prognum [versnum]
     rpcinfo -a serv_address -T transport prognum [versnum]
     rpcinfo -b [-T transport] prognum versnum
     rpcinfo -d [-T transport] prognum versnum

DESCRIPTION

     The rpcinfo utility makes an RPC call to an RPC server and reports what it finds.

     In the first synopsis, rpcinfo lists all the registered RPC services with rpcbind on host.  If host is not specified, the local host is the
     default.  If -s is used, the information is displayed in a concise format.

     In the second synopsis, rpcinfo lists all the RPC services registered with rpcbind, version 2.  Also note that the format of the information
     is different in the first and the second synopsis.  This is because the second synopsis is an older protocol used to collect the information
     displayed (version 2 of the rpcbind protocol).

     The third synopsis makes an RPC call to procedure 0 of prognum and versnum on the specified host and reports whether a response was received.
     transport is the transport which has to be used for contacting the given service.	The remote address of the service is obtained by making a
     call to the remote rpcbind.

     The prognum argument is a number that represents an RPC program number If a versnum is specified, rpcinfo attempts to call that version of
     the specified prognum.  Otherwise, rpcinfo attempts to find all the registered version numbers for the specified prognum by calling version
     0, which is presumed not to exist; if it does exist, rpcinfo attempts to obtain this information by calling an extremely high version number
     instead, and attempts to call each registered version.  Note: the version number is required for -b and -d options.

OPTIONS

     -T transport
	     Specify the transport on which the service is required.  If this option is not specified, rpcinfo uses the transport specified in the
	     NETPATH environment variable, or if that is unset or empty, the transport in the netconfig(5) database is used.  This is a generic
	     option, and can be used in conjunction with other options as shown in the SYNOPSIS.

     -a serv_address
	     Use serv_address as the (universal) address for the service on transport to ping procedure 0 of the specified prognum and report
	     whether a response was received.  The -T option is required with the -a option.

	     If versnum is not specified, rpcinfo tries to ping all available version numbers for that program number.	This option avoids calls
	     to remote rpcbind to find the address of the service.  The serv_address is specified in universal address format of the given trans-
	     port.

     -b      Make an RPC broadcast to procedure 0 of the specified prognum and versnum and report all hosts that respond.  If transport is speci-
	     fied, it broadcasts its request only on the specified transport.  If broadcasting is not supported by any transport, an error message
	     is printed.  Use of broadcasting should be limited because of the potential for adverse effect on other systems.

     -d      Delete registration for the RPC service of the specified prognum and versnum.  If transport is specified, unregister the service on
	     only that transport, otherwise unregister the service on all the transports on which it was registered.  Only the owner of a service
	     can delete a registration, except the super-user who can delete any service.

     -l      Display a list of entries with a given prognum and versnum on the specified host.	Entries are returned for all transports in the
	     same protocol family as that used to contact the remote rpcbind.

     -m      Display a table of statistics of rpcbind operations on the given host.  The table shows statistics for each version of rpcbind (ver-
	     sions 2, 3 and 4), giving the number of times each procedure was requested and successfully serviced, the number and type of remote
	     call requests that were made, and information about RPC address lookups that were handled.  This is useful for monitoring RPC activi-
	     ties on host.

     -n portnum
	     Use portnum as the port number for the -t and -u options instead of the port number given by rpcbind.  Use of this option avoids a
	     call to the remote rpcbind to find out the address of the service.  This option is made obsolete by the -a option.

     -p      Probe rpcbind on host using version 2 of the rpcbind protocol, and display a list of all registered RPC programs.	If host is not
	     specified, it defaults to the local host.	Note: Version 2 of the rpcbind protocol was previously known as the portmapper protocol.

     -s      Display a concise list of all registered RPC programs on host.  If host is not specified, it defaults to the local host.

     -t      Make an RPC call to procedure 0 of prognum on the specified host using TCP, and report whether a response was received.  This option
	     is made obsolete by the -T option as shown in the third synopsis.

     -u      Make an RPC call to procedure 0 of prognum on the specified host using UDP, and report whether a response was received.  This option
	     is made obsolete by the -T option as shown in the third synopsis.

EXAMPLES

     To show all of the RPC services registered on the local machine use:

	   example% rpcinfo

     To show all of the RPC services registered with rpcbind on the machine named ``klaxon'' use:

	   example% rpcinfo klaxon

     The information displayed by the above commands can be quite lengthy.  Use the -s option to display a more concise list:

	   example$ rpcinfo -s klaxon

     program   version(s)   netid(s)		     service	owner
     100000    2,3,4	    unix,tcp,udp,tcp6,udp6   rpcbind	super-user
     100008    1	    udp,tcp,udp6,tcp6	     walld	super-user
     100002    2,1	    udp,udp6		     rusersd	super-user
     100001    2,3,4	    udp,udp6		     rstatd	super-user
     100012    1	    udp,tcp		     sprayd	super-user
     100007    3	    udp,tcp		     ypbind	super-user

     To show whether the RPC service with program number prognum and version versnum is registered on the machine named ``klaxon'' for the trans-
     port TCP use:

	   example% rpcinfo -T tcp klaxon prognum versnum

     To show all RPC services registered with version 2 of the rpcbind protocol on the local machine use:

	   example% rpcinfo -p

     To delete the registration for version 1 of the walld (program number 100008) service for all transports use:

	   example# rpcinfo -d 100008 1
     or
	   example# rpcinfo -d walld 1

SEE ALSO

     rpc(3), netconfig(5), rpc(5), rpcbind(8)

BSD
								  August 18, 1992							       BSD

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